Skip to main content


Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


The Los Angeles County Sanitation Districts (the Districts) are converting several water reclamation plants to nitrification/denitrification (N/DN) mode. Ammonia addition is necessary to prevent breakpoint chlorination and formation of trihalomethanes (THMs), and the dose needs to be kept to a minimum to comply with its own discharge limit. The ability to regulate the ammonia concentration in an N/DN plant effluent is crucial in complying with the stringent limits of ammonia, total coliform, and THMs.

A research project was recently completed at the Districts to study chloramination of N/DN effluent. The findings of this study include (1) ammonia added to the secondary effluent channel was well mixed hydraulically before chlorine addition; (2) the N/DN effluent exerted significant chlorine demand shortly after chlorine addition; (3) the Cl2:NH3-N ratio at the breakpoint of chlorination was found to be around 11, higher than the theoretical ratio of 7.6; (4) THMs formation dropped as the ammonia concentrations increased; (5) approximately 20% of the added ammonia was lost during the chlorination process; and (6) split chlorination had insiginificant impacts on THMs formation and chlorine residuals when chloramination was applied. This study generated useful and practical information for chloramination of N/DN effluent to meet stringent discharge requirements.

Document Type: Research Article


Publication date: 2003-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more